Breaker failure relay REB 010

Transcription

1 Page 1 Issued June 1999 Changed since July 1998 Data subject to change without notice (SE970138) Features Local redundant protection when the circuit breaker does not operate The technique with microprocessors makes the relay REB 010 very flexible for different applications REB 010 is possible to use both with line and bus protections Initiates tripping of adjacent breakers in order to isolate the faulty section and maintain stability in the network Accurate, consistent, short operating times and high overload capacity Evolving faults can be detected Application Breaker failure relays are required to give a rapid trip when the primary circuit breaker does not break properly at e.g. a short circuit in the network. The faulty section of the network could in this way be tripped separately. It is very important that the circuit breaker operates correctly in order to remove the fault rapidly. There is, however, always a risk that the breaker does not succeed in breaking the fault current and the total fault time is then dependent upon the trip time of the adjacent circuit breaker. One simple and reliable way to secure the isolation of a fault is to check the current after a set time. The time should then be long enough to enable the circuit breaker to operate. The tripping impulse to the circuit breaker from line or bus protections gives simultaneously also a start impulse to the breaker failure relay. In case that the current through the circuit breaker after the set time still exceeds the set current level, the breaker failure relay gives a trip impulse to adjacent breakers. Breaker failure relays used together with either line or bus protections has somewhat different requirements for start and retrip. REB 010 can easily be adjusted to these different requirements. In stations with two or more busbars with switched lines it is normal to arrange so that the trip impulse passes the line reconnection relay in the bus protection to give trip to the correct bus.

2 Page 2 Design Basic principle for a breaker failure relay The basic principle for a breaker failure relay is shown in Fig. 1. An earth fault occurs on line L X. The distance protection Z LX detects the fault and sends a trip impulse to the line circuit breaker. Simultaneously a start impulse is given to the breaker failure relay (BFR). After a set time the current passing the circuit breaker in line L X is checked. If the current I X1 has been interrupted the circuit breaker has operated correctly. If the current I X1 still flows, the breaker has not operated correctly. After a set time delay, a trip impulse is transmitted to the adjacent circuit breakers in lines L A and L B. In order to detect faults in the dead zone between the circuit breaker and its current transformer the breaker failure relay can also initiate a trip impulse to the other line end. Similarly, a bus fault followed by a breaker failure could be tripped. The operate time of a breaker failure relay depends on different parameters as can be seen in Fig. 2. Two different applications are shown on time curve 1 and 2. Fig. 2 shows an example of fault-clearing times for a breaker failure. The circuit breaker will normally trip all fault currents within 40 to 60 ms. A margin of 20 ms, or more, should always be added between column 2 and 3 i.e. time for an additional zero crossing of the primary current must always be there to ensure tripping of a fault. Time curve 1 shows the normal fault-clearing time for a majority of the networks with for example the following requirements: - where the stability of the system could be maintained also after a fault time up to 200 ms - where the line protections has a second step with a time delay of 300 ms or more - where all circuit breakers has a guaranteed opening time of 3 cycles ( 60 ms). Time curve 2 is applicable when system stability is of large importance and when the circuit breakers has a guaranteed opening time within 2 cycles ( 40 ms). 1. Operate time of line protection. 2. Opening time of circuit breaker. 3. Set time of BFR plus aux. relays (margin > 20 ms). 4. Measuring time of breaker failure relay. 5. Trip relays (2x5 ms). 6. Opening time for adjacent circuit breakers. Fig. 1 Basic principle for a breaker failure relay ( )

3 Page 3 ( ) Fig. 2 Operate time of a breaker failure relay

4 Page 4 Design (cont d) REB 010 Breaker failure relay REB 010 consists of the following parts RXTP 18 Test switch 109 RXTUG 22H Dc/dc converter 119 RLIC 100 Breaker failure relay Breaker failure relay RLIC is shown on the logic scheme on the next page. It is used both with line and bus protections. When the breaker failure relay is used together with bus protection it is normally set for - three phase start - three phase tripping - impulse seal-in of start indication at trip When the breaker failure relay is used together with line protection it is normally set for - one- or three phase start - single phase tripping - impulse seal-in of start indication at start ( ) Fig. 3 Logic diagram

5 Page 5 RLIC breaker failure module RK AB Breaker failure module RLIC represents the measuring unit for one line. Indication for the relay IN SERVICE is made with green LED. The self-supervision of the internal logic circuits gives its indication on internal failure as flashing of this green LED. Indication for started phase is done with yellow LED while indication for trip is red. Indications In service Start of individual phase With the switch Start target you could set ON OFF Impulse seal-in after external start impulse Impulse seal-in after trip impulse With the switch Retrip delay either instantaneous or delayed retrip could be achieved. The breaker failure relay has two time settings. t 1 represents the additional delay for breaker failure check. t 2 represents the extra time delay until trip impulse is given. The total time delay until trip impulse is given is defined as (50 +t 1 +5t 2 ) ms. The breaker failure relay has a trip impulse length of 100 ms. Trip Settings Start of target ON/OFF Time setting t 1 0/80/160/240 ms Retrip 0/50 ms Time setting 50 + t 1 + (t 2 x 5) ms Current setting (0,1-2) x rated current Reset ( ) REB 010 used together with bus protection When the breaker failure protection is used together with bus protections the modules for all lines are mounted together into one complete unit. The design of the unit itself is identical in the different versions. It is only the facilities for testing the breaker failure protection that requires different solutions. The ordering numbers for the different versions do not contain any BFR-measuring units type RLIC, why these have to be specified separately as number of lines.

6 Page 6 Design (cont d) Compact version RK AA This unit consists of a ready connected relay rack size for 1-10 lines with one test switch RTXP 18, one dc-switch, one dc/dcconverter RXTUG 22H, one RXME 1 heavy duty relay, one test position for RLIC plus space for one BFR measuring unit type RLIC for each line up to 10. When testing one BFR measuring unit the test handle RTXH 18 is plugged in, the dcvoltage is switched off and the BFR measuring unit type RLIC to be tested is removed from the normal position and plugged into the test slot position. After that the testing is completed via the test handle RTXH 18 and the test switch RTXP 18. After testing the BFR measuring unit type RLIC is removed from the test position and plugged back into the normal position again. 19 (84 TE) I > 101 RXTP 18 Test switch 109 RXTUG 22H Dc/dc converter 119 BFR test Terminal slot , 131, 137, 143, 149, 155, 161, 167, 173, 179 RLIC 100 BFR measuring unit 501 Selector switch unit 509 RXME 1 Auxiliary relay 512 RTXE Diode block Complete version RK AA This unit consists of a ready connected relay rack size for 1-5 lines with one dcswitch, one dc/dc-converter RXTUG 22H, one RXME 1 heavy duty relay, and with space for one test switch RTXP 18 and one BFR measuring unit type RLIC for each line up to 5. The complete version for up to 5 lines is built up to enable that testing of incoming currents and opening of trip circuits are made by using a test switch for each BFR measuring unit. This version is used when independent testing per breaker failure protection is required, and all testing is done in the normal way with the aid of the test handle RTXH 18 and the test switch RTXP 18. Tripping of the circuit breakers is normally made via the trip relays in the busbar protection. 19 (84 TE) I > 101, 109, 119, 127, 137 RXTP 18 Test switch 145 RXTUG 22H Dc/dc converter 155, 161, 167, 173, 179 RLIC 100 BFR measuring unit Selector switch unit 509 RXME 1 Auxiliary relay 512 RTXE Diode block

7 Page 7 Complete version RK AB This unit consists of a ready connected relay rack size and a ready connected relay rack size 4U for 6-10 lines with one dc-switch, one dc/dc-converter RXTUG 22H, one RXME 1 heavy duty relay, and with space for one test switch RTXP 18 and one BFR measuring unit type RLIC for each line from 6 to 10. The complete version for 6 to 10 lines is built up to enable that testing of incoming currents and opening of trip circuits are made by using a test switch for each BFR measuring unit. This version is used when independent testing per breaker failure protection is required, and all testing is done in the normal way with the aid of the test handle RTXH 18 and the test switch RTXP 18. Tripping of the circuit breakers is normally made via the trip relays in the busbar protection. 19 (84 TE) I > 109 RXTUG 22H Dc/dc converter 125, 131, 137, 143, 149, 155, 161, 167, 173, 179 RLIC 100 BFR measuring unit 501 Selector switch unit RXME 1 Auxiliary relay 512 RTXE Diode block , 707, 713, 719, 725, 731, 737, 743, 749, 755 RXTP 18 Test switch 4U Without test switch version RK AA This unit consists of a ready connected relay rack size for 1-10 lines with one dcswitch, one dc/dc-converter RXTUG 22H, one RXME 1 heavy duty relay, and with space for one BFR measuring unit type RLIC for each line up to 10. The unit does not contain any method for periodic test, and such arrangements should preferably be added. 19 (84 TE) I > 109 RXTUG 22H Dc/dc converter 125, 131, 137, 143, 149, 155, 161, 167, 173, 179 RLIC 100 BFR measuring unit 501 Selector switch unit RXME 1 Auxiliary relay 512 RTXE Diode block

8 Page 8 Design (cont d) Line protection version RK AA This unit consists of a ready connected cassette size 35TE and apparatus bar assembly with one dc-switch, one dc/dc-converter RXTUG 21H, one RXME 1 heavy duty relay, one test switch RTXP 18 and one BFR measuring unit type RLIC. Note: this unit includes the BFR measuring unit type RLIC, why it shall not be ordered separately. The line protection version is built up to enable that testing of incoming currents and opening of trip circuits are made by using the local test switch. This version is used when a separate breaker failure protection with independent testing per breaker failure protection is required, and all testing is done in the normal way with the aid of the test handle RTXH 18 and the test switch RTXP 18. Tripping of the circuit breakers is normally made via the trip relays in the busbar protection. Additional high speed trip relays type RXMS 1 with 6 no contacts can easily be added, stronger contacts are obtained through the addition of type RXME 1 relay in parallel. 35 TE I > 104 RTXP 18 Test switch 112 RXTUG 22H Dc/dc converter 124 RLIC 100 BFR measuring unit 504 Selector switch unit 512 RXME 1 Auxiliary relay 515 RTXE Diode block Trip contact reinforcement This unit consists of a ready connected apparatus bar assembly size 4U 12C with one RXMM 1 auxiliary relay, one RXME 1 heavy duty relay, and one RXTDA 1 diode unit. The unit is used for contact reinforcement of line trip units in 2-zone busbar protections for up to 4 lines. By adding one more RXTDA diode unit up to 8 lines can be accommodated in the basic 12C apparatus bar assembly. The unit can be extended with apparatus bars, relay bases and RXTDA diode units in groups of 4 lines, providing a maximum of 56 lines in a 60C apparatus bar assembly. 12C U RXMM 1 Auxiliary trip bus selection relay 107 RXTDA 1 Diode unit with 8 diodes for 4 lines 301 RXME 1 Heavy duty relay 307 (RXTDA 1) (Diode unit with 8 diodes)

9 Page 9 Technical data Rated current current range Operating time Measuring time Time range Rated frequency Current carrying capacity continuous 1 s Burden per phase at 0,1 x I r at 1,0 x I r Auxiliary voltage 0,5, 1 or 5 A (0,1-2) x I r 8-15 ms approx. 2 ms ms in steps of 5 ms 50 or 60 Hz 4 x I r 100 x I r 0,03 VA 1,0 VA V dc V dc V dc Permitted ambient temperature -5 C to +55 C Insulation tests: Dielectric tests Impulse voltage test Disturbance test: 1 MHz test 2,5 kv, 1 MHz, 2 s Data for trip contact max. service voltage closing current continuous current 2.0 kv, 50 Hz, 1 min or 1,0 kv over open contact 5 kv, 1,2/50 µs 250 V ac/dc 15 A 5 A

10 Page 10 Ordering Specify: Auxiliary dc supply voltage EL 48/60 V 110/125 V 220/250 V Rated current IN 0,5 A 1 A 5 A Number of lines: Compact version max 10 lines RK AA Quantity: Complete version max 5 lines RK AA Complete version 6-10 lines RK AB Without test switch version max 10 lines RK AA Line protection version RK AA Additional units for REB 010: BFR measuring module type RLIC V dc Specify rated current IN 0,5 A 1 A 5 A RK AB BFR measuring module type RLIC V dc Specify rated current IN 0,5 A 1 A 5 A RK BB BFR measuring module type RLIC V dc Specify rated current IN 0,5 A 1 A 5 A RK CB User s Guide for REB 010 1MDU05007-EN For our reference and statistics we would be pleased if we are provided with the following application data: Country: End user: Station name: Voltage level: kv References COMBIFLEX Relay accessories and components COMBITEST Test system 1MRK BEN 1MRK BEN Manufacturer ABB Automation Products AB Substation Automation Division SE Västerås Sweden Tel: +46 (0) Fax: +46 (0)